Dresser for grinders



Aug. 17, 1943. L. M. JONES ETAL 2,327,272

DREssER Fon GRINDERS F/iled Jan. 27, 1941 :s sheets-sheet 1 Aug. 17, 1943. 1 M. JONES ET AL 2,327,272

DRESSER FOR GRINDERS Filed Jan. 27, 1941 3 Sheets-Sheet 2 A Zn M frime/25ans: "2@ 17 j Afname? :g/zggj n H4 Z @af Tirada/15am, w25/fesses: m, Zig Mm M Aug. 17, 1943, L. M. JONES ETAL DRESSERv FOR GRINDERS Filed Jan. 27, 1941 5 Sheets-Sheet 5 mim Patented Aug. 17, 1943 OFFICE DRESSER FOR GRINDERS Lawrence M. Jones and Halvor E. Anderson, Harvey, Ill.

Application January 27, 1941, Serial No. 376,048

Claims.

This invention relates to a dresser for grinders or grinding Wheels.

The object of the invention is to provide a novel device or attachment for application to the table on a surface grinder for dressing the grinding Wheel or disk which is usually of abrasive material so that the irregular or uneven edges of the grinding wheels may be dressed to any particular curved, straight or angular shape.

Another object of the invention is to provide a novel, simple, inexpensive, lightweight, small and compact device which can be economically produced and assembled from a few simple parts for accurately dressing or shaping the operative edge or periphery of grinding wheels either at any desired curvature, convex or concave, straight and angular or beveled, or combinations thereof, initially or after becoming worn by use, so as to accurately grind articles of metal,or otherwise, of various irregular shapes or in nishing such articles, grinding tools or otherw1se.

Another object of the invention is to provide a novel dresser for grinders which can be applied as an attachment to or mounted on the bed plate or work table under and at one side instead of straddling the grinding wheel of a surface grinder or other machine bearing a suitably driven grinding Whee1 usually by means of an individual electric motor, and firmly held in accurately adjusted position with relation to the grinding wheel as by magnetic attraction or otherwise for dressing under the wheel without requiring the removal of the usual grinding wheel or guard and so that the usual dust catcher will remove the dust of finishing and which permits the usual adjustment or feeding of the wheel down on the dresser and Without the necessity or hazard of removing the Wheel or requiring pulling or displacing either the table, work or wheel; which can be easily and accurately manipulated for either straight, angular or arcuate dressing and requires no take-up adjustrnent or lubrication or oil anywhere. The latter feature is especially desirable because it avoids the possibility of spattering oil' on the grinding wheel. One dare not get oil on the hardened or ground surfaces of the wheels.

Still another object of the invention is to provide a novel dresser forgrinding wheels which can be readily adjusted or easily changed for finishing the grinding wheels on a convex or ccncave radius, or straight or angular, that is normal to the face or at any desired angle there- Y to and for accurately adjusting said angle in a single appliance instead of requiring separate devices and which avoids long periods of contact of the diamond finishing tool thereby saving on the diamond which wears comparatively fast,

vthereby reducing the cost of operation.

Still another object of the invention is to provide a novel device or attachment capable of being quickly and interchangeably used for radius dressing either convex or concave, or straight and angular or beveled dressing of a grinding wheel having a frame adjustable on a horizontalaxis to set horizontally or at any angle and which supports a nishing tool for such dressing of the wheel and also serves to support an oscillatable tool support interchangeably usable therewith for arcuate radius dressing, either on a convex or concave arc, and in which a diamond tool may be readily and easily adjusted to vary the radius or the angle as desired, with accuracy, quiclmess and dispatch.

Another object of the invention is to provide a structure embodying a novel relation of parts which obviates the necessity of employing separate devices, one for radius dressing and another for straight and angular dressing or finishing as well as permitting the operations to be accomplished much quicker than has heretofore been possible with most devices on the market, i. e., approximately ten times as fast and without removing the work from the work table.

Another object is' to provide means to permit very accurate adjustment of the angle of bevel of a cut or dressing operation in connection with mathematical calculation. Y

Further objects and advantages will appear and be brought out more fully in the following specication, reference being had to the accompanying drawings, in which:

Fig. 1 is a front elevation showing the grinding wheel dresser in use for grinding on a convex radins, with certain parts broken away and in section; Y

Fig. 2 is an end'elevation thereof;

Fig. 3 is a view simlar to Fig. 1, but showing the device used as a concave radius dresser;

Fig. 4 is an end elevation of the device shown inhFig. 3;

Fig. 5 is a top plan view of the devie'e;

Fig. 6 is a front elevation showing the device in use for straight edge work;

Fig. 7 is an end elevation of the device as shown in Fig. 6;

Fig. 8 is an enlarged detailed view of a supporting arm used in radius dressing;

Fig. is a front elevation of the'device in use for angular dressing;

Fig.

Fig. 12 is a sectional elevation taken on the line |2|2 of Fig. 10;

Fig. 13 is a face view of a degree disk forming part of the device;

Fig. 14 is an enlarged fragmentary vertical sectional elevation of the sliding block or tool support forming part of the device;

Fig. 15 is an end elevation showing the use of additional adjuncts for more accurately adjusting the device for angular dressing;

Fig. 16 is a detailed view of several precision blocks in perspective; and

Fig. 17 is an end elevation showing a slight modification of the tool shifting means.

Referring more particularly to the drawings,

I9 designates the table or bed on a surface grindy er or other suitable machine by which the grinding wheel or disk is supported to be rotated and is usually of metal for supporting the work. The finisher or attachment includes a horizontal metallic base 20 adapted to be magnetically or otherwise held in a ilxed position on the table at right angles or parallel to the wheel or plane thereof, in alignment therewith or at any other suitable position by making the base a permanent magnet or by passing a current through the table. Obviously any other suitable attaching and adjusting means may be employed so as to arrange the device in proper relation to the grinding wheel for action in dressing the same either initially or after the same has become worn, irregular or uneven in use or for use in grinding and polishing certain objects of irregular contour, either convex, concave, plane, beveled or otherwise and so as to exactly fit the shape desired in producing such work or article or for grinding tools. At one end of the base 28 is an upright or standard 2| having a flat circular portion, plate or disk 22, the face of which is fiat and the peripheral edge 23 of which is circular and provided with a central marker 24 at the top. The flat face 25 of the circular portion or disk 22 has a central axial projection or pivot hub 26 through which is provided an axially threaded socket or bore 21 extending through the plate or disk 23 and into the upright 2| as more particularly shown in Fig. 12 of the drawings. A circular degree disk 28 is flat to t against the at face 25 and is also of uniform thickness. This disk 28, as shown in Figs. 12 and 13, has a central circular or axial aperture 29 to fit on the hub 26 and on its peripheral face or edge 30 is provided with calibrations at either side of the center marker 24 beginning at zero to ninety degrees on each side thereof or extending around one-half of the circumference. The flat face 3| of the disk 28 ts against the flat face 25 with the peripheral edges meeting. The disk or face plate 28 is provided on its face 32 with a diametrical key slot or groove 33 adapted to take a pair of keys or blocks 34 on opposite sides of the aperture 29, these blocks being dry tted in the slot or integral therewith and adapted to t and support a horizontal support member or bed plate 35 disposed diametrically of the disk 28 or as the chord of an arc thereof and adapted to be angularly adjusted therewith on a horizontal axis as will be later described. The support 35 Comprises two parts and also constitutes an adjusting element for the tool as will also be later explained. It consists of a relatively thin section or left-hand part 36 and a relatively thick section or right-hand part 31 fitted together. 'I'he part 36 is provided with a slot or groove 38 registering with the slot 33 and the parts 36 and 31 are held together as by means of screws 39 at the slot or groove 38 and preferably countersunk in the face thereof for locking the parts 36 and 31 together. When these parts are so locked, they are mounted on the blocks 34 as will be later explained, and are provided in their coacting faces at the top with an inverted T-slot 40 to take a reciprocating tool holder or block 4| which may be of rectangular form as shown. The block 4| carries a central longitudinal key 42 which is suitably xed thereto as in a groove in the bottom of the block 4| and forms the top or leg end of the inverted T-slot 40 and held by dry pins 42a which may be tapered, if desired, or by any other suitable method. The key 42 enters the narrow part of the inverted T-slot 40 and the block 4| is spring held at the key to reciprocate in the T-slot by means of a key 43 having a threaded aperture 44, the spring held key 43 f1tting the enlargement of the T-slot and being held up against the overhanging portions thereof which form a guideway for slidably supporting the block for movement back and forth transversely across the edge of a grinding wheel. A spring held lock bolt 45 engages the threaded aperture 44 and the shank 46 thereof extends through a hole 41 in the block 4| and the key 42 and through an enlarged bore 48 in the top of the block which accommodates a coiled spring 49'between the bottom of the bore and an enlarged head 50 on the bolt and around the shank thereof so as to hold the key 43 tightly against the overhanging portions of the T-slot and the block down against parts or sections 36 and 31 of the sectional support or bed plate 35. However, there is sufhcient friction to hold the block at any position although it may be easily reciprocated back and forth on the support 35 guided in a rectilinear path in the slot. The tool holder or reciprocating block 4| is provided with a vertical opening or bore 5| for a removable diamond or other tool 11 which is locked by a set screw 52 engaged in a threaded bore at one end of the block. An operating pin 53 is similarly mounted at the opposite end of the block and is locked in its opening or socket by a set screw 54 corresponding to the set screw 52. The support or bed plate 35 is provided with a plurality of spaced horizontal holes 55 shown as five in number equidistantly spaced apart in parallel relation to the axis for mounting and adjusting thesupport 35 longitudinally on the degree disk or face plate 28 lengthwise of the chord of an arc thereof and the standard to vary or adjust the stroke or movement of the tool holder at or toward either side or angle of the support as will be later described. It is held in position by a cap screw or bolt 56 which passes through one of the holes 55 and is shown centrally positioned in the drawings. This bolt 56 is threaded into the socket 21 so as to hold the degree disk 28, as well as the tool holder or reciprocable block 4| and tool carried thereby, as will be later described, at any desired angle together with the support 35 or to adjust the latter longitudinally in any one of the different holes 55 to vary the angle of inclination or projection of the bed plate or support 35 and to increase or decrease the same as desired. By

tightening the bolt 56, the face 25 of the disk 22 and the coacting dat face 3| of the degree disk 28 are tied or clamped tightly together so that the parts can be securely held in any desired anaular position which is indicated by the registration of the marker 24 with the calibrations on the peripheral face of the degree disk 28 and this adjustment may be varied between 180 degrees, that is, zero and ninety degrees or a right angle at either side depending upon the angle of the angular finishing cut or bevel desired to impart to the grinding disk or wheel.

The part or section 31 of the support 35 near its upper face is provided with a longitudinal groove or slot 51 in its outer face opposite the degree disk 28 to slidably receive a spline or reduced projection of a supporting bracket 58, the reduced projection or spline 59 thereof forming a tongue or rail fitting in the groove 51 and locked by any suitablemeans such as screws 80 which pass horizontally through the bracket and into the part 31 which is provided with threaded sockets for this purpose, The supporting bracket 58 is preferably made in the form of an open frame of rectangular outline and plan having extension arms or ears 6| at the ends thereof forming bearing arms from the free ends of which project an upright lever support 62 in the form of an upright cross piece or bar forming a cross member connecting the ears or arms 6I and projecting up above the arms 6l so that its upper face is parallel to and preferably aligns horizontally with the top of the block 4|, although this is not absolutely necessary. The lever support 62 is provided with a plurality of equidistantly spaced sockets 63 adapted to receive corresponding vertical pivotpns including two inner pivot pins 64 and two outer pivot pins 65. While the inner or central pins 64 are. to vary the throw, preferably used for horizontal adjustment of the tool holder or block 4| and the outer pins for adjustment thereof when disposed at an angle for angular or beveled cutting or .dressingof the grinding wheel, there is no limitation in this direction. The supporting bracket 58 at the ends 6| is provided wi'rh'bearing bores 66 to take a horizontal operating shaft and removable pivot 61 to one end of which a depending bracket support or hanger slide 68 is fixed in any suitable way as by providing a socket in the support pinned or otherwise secured to the shaft, the hub of the bracket having a depending arm 69 (see Fig. 8). The depending arm 69 has flanges 18 forming a track way or slide groove therebetween and also has an intermediate vertical slot 1|. One of the flanges is provided with calibrations or graduations shown marked in inches and fractions thereof above and below a central zero point 12 substantially intermediate the ends of the slots 1| with graduations 12a above and graduations 12b below the zero point 12 as related to the pivot axis 61 as will be later described, for producing a concave face or nish on the grinding wheel edge above the center or zero mark 12 and a convex face or edge below said mark as will be later described with the tool above and below the pivot axis 61, respectively. A clamping screw 13 extends through the slot 1| to hold 'an adjustable diamond supporting head 14 at mark 19 is provided on the slidable head 14 to cooperate with the graduations 12a and 12b so that when the tool is adjusted below the shaft 61 as a pivot axis or the mark 19 disposed below the zero mark 12 or along the lower graduations 12b and the shaft together with the tool holder swung on its pivot axis in a vertical arc, the device will dress the edge of the grinding Wheel convexly as shown in Figs. 1 and 2 but when the tool is positioned above the pivot axis of the shaft 61 with the mark 19 above the zero mark 12 instead of below it and cooperating with the upper graduations 12a, corresponding swinging movement of the tool transversely in a path across the edge of the grinding wheel will produce a concave finish as shown in Figs. 3 and 4 of the drawings. The graduations will deter- -mine the radius of the arc which may be adjusted as desired to vary the convex or concave curvature. By way of example, a thirteen-sixteenths radius is shown on the drawings for both convex and concave dressing, but it is to be understood that this radius is not limited and may be adjusted by the means described. The head -14 is provided with an upper threaded socket or bore 88 for receiving the clamping screw 13 through the slot 1| so as to tighten the tool at any particular adjustment, although this adjustment is primarily for convex dressing. screw 13 is engaged in a lower threaded socket or bore 8| in the head 14 spaced below the socket 80 as shown in Figs. 1 to 4, inclusive. As before stated, the shaft 61 is pinned to the bracket support 68 so that when the shaft is oscillated, corresponding rotation will be imparted to the tool 11. 'I'he shaft is held in position against axial movement in the bearings 6|-85 by the hub of the support 68 at one end and a collar 82 at the outside of the opposite cnd or bearing arm 6| and held by a set screw 82a. A removable operating handle or crank 83 is also provided on the projecting end of the shaft and is held in position by a set screw 83a engaging the handle through the end of the shaft.

A lever 84 is provided for reciprocating the block or tool holder 4| and this lever has one or more apertures 85 designed to be engaged with thepins 64 and 65. It is also provided near its inner end with an elongated slot 85 for engaging the pin 53 and where the pin 53 is mounted at the top of the block 4| the pivot hole 85 remote therefrom is used for engaging the pins 64 and 65 as shown in Fig. 5 of the drawings so that by swinging the lever 84 on its pivot, the block 4I may be reciprocated horizontally back and forth across the path or edge of the grinding wheel for straight dressing as shown in Figs. 6 and '1 or angular or beveled dressing as indicated in Fig. 9 with the degree disk or face plate 28 and the support 35 set at an inclined angle and held by the` bolt 56. Adjustment at an opposite angle will change the direction of the bevel. Of course, it is to be understood that should the depending arm 69 and parts carried thereby be in the way, they can be easily removed from the shaft 61 or with the latter by unseating the set screws 82a and 83a and removing ihe collar 82 and the handle or crank 83 so that the shaft can be drawn through its bearings. The lever preferably has a reduced portion 81 to clear the block 4l.

It will thus be seen that the horizontal pivot 55 permits proper rotatable angular adjustment of the support 35 vertically on a horizontal axis at For concave dressing, the clampingv any desired angle either horizontally or inclined at either side, at which positions it may be clamped so that the tool 11 will properly engage a grinder or abrasive grinding wheel or disk 88. A convex edge is shown at 89, a concave edge at 90, a horizontal edge at 9| and an angular or beveled edge at 92 depending upon the dressing angle desired. The tool 11 may be set exactly below the axis of rotation of the grinding wheel or otherwise and moved in a path transversely across the edge thereof, either reciprocated or oscillated back and forth, as described. This may be accomplished by oscillating the shaft 61 or by reciprocating the block or tool holder 4| with the device set at right angles or parallel to the grinding wheel.

In lieu of the pin 53 being mounted directly on the block 4| at the top, it may be mounted as shown in Fig. 17 of the drawings in which instance the pin 93 is of angular or curved formation and fits one or more sockets in the vertical face of the block 4| and supported or limited in its displacement by a, collar 94, the pin being threaded in internally threaded bores or sockets 95 depending upon the adjustment desired at the side 96 of the block 4| instead of at the top. Tapped holes 91 are provided in the ends of the section 31 of the support 35 to take a vertical end plate 98 which is held in position by a cap screw 99 disposed through an aperture in the plate and into the socket 91 as shown in Fig. 15 of the drawings. Precision blocks of suitably accurate thicknesses may be arranged upon the support 35 and block 4| against the end plate 98 and a sine bar |0| arranged upon rollers |02 at its concave ends at the top of the support or block and blocks |00 respectively against the plate 98 but may be disposed horizontally and by means of a suitable precision instrument or caliper set exactly horizontally. This is used where extremely accurate angular setting of the support 35 is desired which perhaps cannot be obtained at the graduations 30 in cooperation with the zero marking 24. By suitable mathematical calculations in connection with the triangle thus erected, namely a right angle triangle, the angle of inclination may be properly determined in connection with the hypothenuse of the triangle, the sine of the angle and the side opposite. In this instance, the face of the sine bar |8| is arranged parallel to the base 20 or table |9 and the precision blocks |00 inserted until the proper angle is obtained. Of course, these parts are removed during the dressing operation. In Fig. 9 of the drawings, the support is set at a thirty degree angle by way of example which is the angle at which the beveled edge 92 is disposed with reference to the horizontal edge 9| but any angle desired may be obtained by the adjustment as described.

Thus, in the operation of the device, by proper angular adjustment of the face plate of degree disk 28 by the screw 56, the tool holder may be set horizontally or at an incline and parallel or transversely to the grinding Wheel so as to operate parallel to or across said edge. Whether set horizontally or at an angle, the tool 11 in the block 4| may be moved in a path across the edge of the grinding wheel to produce a straight edge 9| as shown in Figs. 6 and 7 by oscillating the lever 84 and reciprocating the head 4| and diamond tool 11 carried thereby across said edge and in contact therewith while the device or the Wheel is fed to cutting position. That is, the wheel or the diamond finishing tool is adapted to be fed one toward the other and the invention contemplates means to adjust the diamond or the wheel one toward the other and in an ordinary surface grinder means is usually provided for adjusting the wheel toward the diamond nishing or dressing tool for this purpose. The entire edge of the wheel 88 may be straight as at 9| or entirely beveled as at 92 or partly straight and partly beveled according to the adjustment obtained and the finishing angle desired. For a convex radius, the device is set as shown in Figs. 1 and 2 so as to cause the tool 11 to produce a convex edge when oscillated in an arc across the edge of the grinding wheel 88 as at 89 by oscillating the shaft 61 through the medium of the handle or crank 83.v In this instance, it will be noted that the tool 11 swings in an arc below the axis of the shaft 61 when the support 14 is adjusted downwardly with the clamping screw 13 engaging the upper socket 88. When the support is adjusted so that the clamping screw 13 engages the socket 8|, that is raised as shown in Figs. 3 and 4 of the drawings, the cutting tool 11 will be disposed above the pivot axis of shaft 61 and when the shaft is oscillated, the diamond will take a concave path across the edge of the wheel to correspondingly dress said edge as the wheel is rotated. Thus, it will be noted that the device may be arranged parallel to the plane of the grinding wheel or normally thereto and that the angle of the beveled edge or the curvature or the radius, either concave or convex may be varied as desired and accurately adjusted according to the particular work to be ground or finished and polished and that this work may be eiciently and accurately carried on with a considerable saving in cost of production. Also, attention is called to the fact that with this device, it is not necessary that the work on the table be removed for dressing the grinding wheel, especially on an ordinary form of. tool or gage grinding machine. The only change that may be required is in the height of the grinding wheel above thetable so as to permit going back to the original setting by having the wheel adjustable, especially vertically, for this purpose.

While we have illustrated and described the preferred form of construction for carrying our invention into effect, this is capable of variation and modification without departing from the spirit of the invention. We, therefore, do not wish to be limited to the precise details of construction set forth, but desire to avail ourselves of such variations and modifications as come within the scope of the appended claims.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent is:

1. A dresser for grinders including a base having an upright standard adapted to be held on the work bed of a surface grinder at right angles or parallel to the grinding wheel thereof and having a flat vertical face plate, a flat faced disk against the face plate and pivoted thereto on a horizontal axis, a support fixed to the face plate across the axis thereof. a tool holder slidably mounted thereon parallel to the face plate and perpendicular to the pivot axis and for adjustment to horizontal or oppositely inclined positions, a plurality of pivots carried by the support outwardly of the tool holder and a lever interchangeably engageable on said pivots and with the tool holder to reciprocate the same on the support.

2. A dresser for grinders including a base, an

upright on the base having a flat circular disk, a degree disk pivoted axially on the first disk for adjustment in a horizontal position or inclined at either side thereof, a support slidably mounted diametrically as the chord of an arc on the degree disk and to be clamped by the horizontal pivot axis thereof in adjusted position lengthwise, said support having `a guide-way at the top, a tool holding block slidably engaged with the guide-way, said support having an outward extension, a plurality of spaced pivot pins on the extension and a lever interchangeably pivotable on said pins and having a slotted end for engagement with a pin on the block to reciprocate the latter and tool carried thereby.

3. I-n a dresser for grinders, a base having an upright standard adapted to be held on the work bed of a surface grinder at right angles or parallel to the grinding wheel thereof, and having a fiat vertical face plate, a flat plate against the face plate and pivoted horizontally thereto, said pivot constituting clamping means to hold the second plate adjusted in a horizontal position or inclined at either side, a support mounted on the second plate against turni-ng independently thereof for angular adjustment therewith, said support being longitudinally adjustable on the second plate and held by said clamping means in adjusted position, a tool holder slidably retained at the top of the support for movement longitudinally thereof parallel to the plates and a lever pivoted on the support in spaced relation to the tool holder and engaging the latter at one end of the lever to reciprocate the tool holder.

4. A dresser for grinders including a base, an upright on the base having a flat vertical plate, a degree disk pivoted horizontally and axially on the plate transversely thereof for adjustment at various angles on said pivot in a horizontal position or inclined on either side thereof, a support slidably mounted diametrically on and against the upper portion of the face of the disk and adjustable to a plurality of longitudinally fixed positions and adapted to be clamped in either of said positions, said support being held against turning relative to said degree disk and having a rectilinear guideway at the top, a tool holder having an extension slidably mounted in the guideway on the support, and a lever adapted to be pivoted in a plurality of different positions on the support and engageable with the tool' holder at a plurality of points certain of which vary in radial length from the pivot to the points of engagement thereof with the tool holder to reciprocate the latter in paths of different lengths.

5. A dresser for grinders including a base, an upright on the base having a vertical flat circular disk, a vertical degree disk pivoted horizontally and axially on the fixed disk for adjustment at various vertical angular positions horizontally or inclined at either side thereof and adapted to be fixed by said pivot in either position, a support splined and slidably mounted diametrically as the chord of an arc on the degree disk, said horizontal pivot axis comprising a bolt extending through the second disk and support and engaged in the xed disk to clamp both in an adjusted position relatively and the support lengthwise, said support having a guideway at the top and a plurality of spaced holes to adjust the support lengthwise with the bolt, a tool-holding blockslidably engaged with and resiliently retained in the guideway against the support and a lever pivoted on the support and to the block to reciprocate the latter.

LAWRENCE M. JONES. HALVOR E. ANDERSON. 

